If in a person functional residual capacity (FRC) is 2300 ml, residual volume (RV) is 1200 ml and inspiratory capacity (IC) is 3500 ml then find out its vital capacity (VC)-

Options

A. 5800 ml
B. 7000 ml
C. 4600 ml
D. 2300 ml

Answer

To find the vital capacity (VC) of a person given the functional residual capacity (FRC), residual volume (RV), and inspiratory capacity (IC), we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Given Values**:
- Functional Residual Capacity (FRC) = 2300 ml
- Residual Volume (RV) = 1200 ml
- Inspiratory Capacity (IC) = 3500 ml

2. **Understand the Relationship of FRC**:
- FRC is the sum of the Expiratory Reserve Volume (ERV) and Residual Volume (RV).
- Formula: FRC = ERV + RV

3. **Calculate Expiratory Reserve Volume (ERV)**:
- Rearranging the formula gives us: ERV = FRC - RV
- Substitute the values: ERV = 2300 ml - 1200 ml = 1100 ml

4. **Understand the Relationship of Inspiratory Capacity (IC)**:
- IC is the sum of Tidal Volume (TV) and Inspiratory Reserve Volume (IRV).
- Formula: IC = TV + IRV

5. **Assume Tidal Volume (TV)**:
- Tidal Volume (TV) is typically around 500 ml.
- Therefore, we can find IRV: IRV = IC - TV
- Substitute the values: IRV = 3500 ml - 500 ml = 3000 ml

6. **Calculate Vital Capacity (VC)**:
- VC is the sum of ERV, TV, and IRV.
- Formula: VC = ERV + TV + IRV
- Substitute the values: VC = 1100 ml + 500 ml + 3000 ml = 4600 ml

7. **Conclusion**:
- The Vital Capacity (VC) of the person is 4600 ml.

### Final Answer:
**Vital Capacity (VC) = 4600 ml**

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